public class Main {
    public static void main(String[] args) {
        Student student1 = new Postgraduate("ysy", 18, "English");
        Student student2 = new Undergraduate("mml", 20);
        student1.introduce();
        student1.study();
        student2.introduce();
        student2.study();
        StudentText.SerializationExample();
        StudentText.Deserialization();
    }
}
